EVALUATION OF STRENGTH CHARACTERISTICS OF ENDOCROWNS FROM HYBRID CERAMICS

Abstract

Background: Restoration of teeth after endodontic treatment is an urgent problem. There is a large selection of materials and structures for dental restoration after endodontic treatment. Aim: This work aimed to determine the strength characteristics of endocrowns made of hybrid ceramics, depending on various conditions. Methods: The study involved 40 samples of removed teeth (mandibular molars). Mechanical and medical treatment of root canals was previously carried out in the teeth, after which the root canals were sealed with a sealer and gutta-percha. The defect in the crown part of the tooth was repaired with a hybrid ceramic endocrown. Endocrowns were made by milling. The endorocrowns were cemented according to the standard cementation protocol for ceramic restorations. All tooth samples were divided into 2 groups of 20 teeth each group. Group 1 was placed in the thermostat for 24 hours at a temperature of +37±1°C, and group 2 was subjected to thermal cycling. After that, the samples of the studied groups were subjected to uniaxial compression until the moment of destruction. The measurements of the maximum load (kN), maximum stress (MPa), and % of deformation at the moment of failure were carried out. All the results obtained were statistically processed. Results and Discussion: According to the results of the study, the samples of group 1 showed higher values of strength and elasticity than samples of group 2. Conclusions: Thus thermocycling, which simulates the natural oral environment negatively affects the durability of the hybrid ceramic. However, the obtained values make it possible to use it for the restoration of teeth after endodontic treatment